|With all the choices out
there, deciding which binocular, spotting scope or riflscope
meets your needs can be downright overwhelming. It doesn't
need to be. Spending a little time learning about the features
found in quality binoculars can help you compare products with
First, you will want to make sure the product you choose
offers the best optical performance and features for a price
you can afford. After all, optical products are a long-term
investment, and it only makes sense to make sure you are
getting your money's worth. By taking the time to learn about
Kruger Optical's products, you are taking a smart first step
in finding a product with optimal value.
It also makes sense to look at products designed for the
activities you do most. For example, marine binoculars are
generally waterproof and made with large objective lenses for
maximum light-gathering on the water, while binoculars for
wilderness enthusiasts are often extra sturdy and lightweight.
Magnification: The first number in a product's model
description describes its magnification. For instance, a 7x50
binocular magnifies objects 7 times. Magnification is
sometimes referred to as "power," as in "7-power." For "zoom"
style products, magnification is expressed as a range. For
example, a 15-45x60 spotting scope magnifies objects to appear
from 15 to 45 times larger than when viewed with a naked eye.
Ideal magnification depends on the activity. Higher
magnification can make an image tend to "jump around," and may
require a tri-pod for stability. Higher magnification also
results in a smaller field of view. Often, products that are
intended for use in a moving environment such as a boat have
relatively low magnification (which is why marine binoculars
typically are 7-power). Products for activities such as bird
watching, where a tri-pod can be used, often have higher power
(typically 10-power for binoculars). Consumers should
carefully consider which factors are most important to them
when choosing their preferred magnification.
Objective size: The second number in the model
description refers to the size of the objective lens (the
large lens farthest from the eye), expressed in millimeters.
For instance, a 7x50 binocular has a 50mm objective. Large
objectives gather more light than small ones, and the image
from a large objective tends to be easier to view. On the
other hand, a small objective makes a product more compact.
Optical coatings and light transmission: All high quality
optical products receive coatings to reduce the amount of
light that is reflected away from the user and to increase
light transmission. Quality optical coatings distinguish
higher-end products because they greatly improve the
brightness and clarity of the image you see. Coatings are an
important factor determining the price of a product, as well
as performance. Coating types include:
C-Coated optics. Single layer
coating on at least the outside lenses. Visible system
FC-Fully coated optics. Single layer coating on all
lens and prism surfaces. Visible system transmission:
MC?Multi-coated optics. Multiple coating layers on
all external surfaces; single layer on internal surfaces.
Visible system transmission: 75-85%.
FMC?Fully multi-coated optics. Multiple coating
layers on all surfaces. Visible system transmission: 80-90%.
BBAR?Broadband multi-layer coating. All surfaces
receive high performance multi-layer coating. Visible system
Optical glass: Lenses and prisms made
from high quality optical glass deliver better image sharpness
than lower-grade glass. Prisms made from BaK-4 glass are
considered best for image brightness. BK-7 prisms also perform
Prism types: Modern binoculars contain prisms to
correct image orientation; without them, objects would appear
upside down. Most binoculars are made with either porro prisms
or roof prisms. Porro prisms give binoculars their traditional
offset shape, with the objective lenses set wider than the
eyepieces. Roof prisms give binoculars a straight appearance,
with parallel barrels. Porro prisms usually offer the best
optics for the price, but they can be heavy and bulky. Roof
prisms have a more compact, streamlined shape. Often, prism
style is a matter of personal preference.
Eye relief: Eye relief refers to the distance between
the eyepiece and the spot where the full image is most
comfortably viewed (where your eyes go). Customers who want to
use their products while wearing eyeglasses (or sunglasses)
should look for long eye relief (at least 16mm).
Eyecups: Many binoculars are equipped with either
fold-down rubber eyecups or twist-up eyecups, so they can be
comfortably used with or without eyeglasses.
Waterproofing: Products intended for outdoor or marine
use are often water resistant or waterproof. Waterproof
products are O-ring sealed and filled with dry nitrogen or
argon to prevent fogging. Waterproof products are made to
withstand prolonged submersion. Water resistant products are
designed to withstand wet weather, but not submersion.
Shock proofing: Shockproof products have been
ruggedized to survive being dropped or, in the case of a
riflescope, to hold a point of aim after rifle discharge.
Field of view: Field of view can be measured in degrees
or as a number of feet that can be seen at 1,000 yards. Lower
magnification products usually have larger fields of view.
Some products are specially designed to have a wide field of
Close focus: Close focus refers to how close an object
can be while still remaining in focus. Being able to focus on
nearby objects is important for such activities as bird
watching and wildlife viewing.
Windage and elevation: These adjustments pivot a
riflescope's erector system to place the reticle in line with
the bullet impact point. Adjustments are typically in ? minute
intervals or ?" at 100 yards.
Other factors: Optics products should be rugged enough
to withstand their intended use. Products should also look
good and feel comfortable with prolonged use. Rubber armor
housing helps prevent heat transfer, making products
comfortable to handle in cold conditions. Quality binoculars
have diopter adjustments, so users can adjust for vision
differences between their two eyes.